Projectile propelling spring gun



Oct. 28, 1969 0, BECK 3,474,770 I PROJECTILE PROPELLIfiG SPRING GUN Original Filed Aug. 19, 1965 BERNARD O. BECK INVENTOR.

ATTORNEY United States Patent 3,474,770 PROJECTILE PROPELLING SPRING GUN Bernard 0. Beck, P.0. Box 272, Arlington, Tex. 76010 Original application Aug. 19, 1965, Ser. No. 481,041, now Patent No. 3,354,559, dated Nov. 28, 1967. Divided and this application June 26, 1967, Ser. No. 648,900

Int. Cl. F411? 7/00; F41c 19/00 US. Cl. 124-26 1 Claim ABSTRACT OF THE DISCLOSURE A gun for propelling a ball projectile having a hole therethrough, the construction including a horizontal support rod, said support rod being rigidly supported at one end, a guide rod on the remaining end of said support rod for slidably receiving said ball projectile, a tubular ram slidably mounted on said support rod, a spring urging said tubular ram to a position at least partly over said guide rod, and a trigger releasing said spring means.

This application is a division of my copending application, Ser. No. 481,041, filed Aug. 19, 1965, now U.S. Patent No. 3,354,559, issued Nov. 28, 1967.

This invention relates to a projector for use with ballistic pendulums for demonstrating to students and others the principle of conservation of motion. Particularly, the invention is directed to improvements in projectors for ballistic pendulums such as illustrated and described in expired US. Patent No. 1,636,234, which issued July 19, 1927.

A first experiment is carried out by impact of a projectile of known mass in a pendulum bob of known mass, noting the resulting height of the bob and projectile after impact, and then determining the velocity of the projectile. A second experiment is then performed to check the velocity thus found, and which second experiment has to do with propelling the same projectile from the same gun and measuring time and distance without the use of the pendulum.

The primary object of the invention is to provide a gun to project a ball.

A particular object of the invention is to provide a ball projecting gun that is mounted on a platform.

Another object of the invention is to provide a gun that will project a ball with improved accuracy.

These and other objects of the invention will become apparent from the following description and the accompanying drawing, in which:

FIGURE 1 is a side elevational view of a ballistic pendulum according to the present invention.

FIGURE 2 is a fragmentary end elevational view of the upper portion of FIGURE 1.

FIGURE 3 is a longitudinal sectional view of the pendulum hob and showing the ball projectile receiving and centering mechanism.

FIGURE 4 is a sectional view taken on lines 44 of FIGURE 1, and additionally showing the projectile receiving end of the bob in elevation relative to the rack on the rack mount.

FIGURE 5 is a longitudinal vertical sectional view of the spring actuated gun for propelling the projectile.

FIGURE 6 is an enlarged fragmentary perspective view of the forward operating parts of the gun.

FIGURE 7 is an enlarged perspective view of the ball projectile, and

FIGURE 8 is a sectional view taken on line 88 of FIGURE 2.

The ballistic pendulum shown includes an elongate base 10, a mast 11 on one side of the base between the ends thereof, a gun mechanism 12 on one end of the base and an upwardly and outwardly extending rack mount 13 on the other end. Projecting from the upper end of the mast 11, and at a right angle with reference to the length of the base 10, there is a tubular housing 14 wherein there is a shaft 15 which is mounted for free rotation by means of ball bearings 16 on its ends. The lower and side portions of the shaft housing 14 are cut away, at 17, to accommodate a triangular truss type pendulum arm 18. The upper end of the arm 18, which is the base end of an isosceles triangle, is detachably secured to the shaft 15 within the cutaway 17 by means of a threaded projection 19 on the shaft and a tubular nut 20 on the projection. As shown in FIGURE 8, the shaft 15 and the horizontal upper end of the arm 18 have interfitting grooves 21 which are step milled so that it would be unlikely that a student would put the arm on the shaft backwards. The pendulum arm 18 is preferably of aluminum or other lightweight but sturdy material. On the lower end of the arm 18 there is a cylindrical pendulum bob 22, the axis of which is parallel with the length of the base 10. As best shown in FIGURES 3 and 4, there are three longitudinal equally spaced radial grooves 23 in the inner wall of the bob 22, which grooves hingedly receive steel plates 24 for catching a ball projectile 25 propelled by the gun mechanism 12. Each plate 24 is pivotally mounted at its forward end by a transverse pin 26, and the inner edge of each plate intermediate its end is arcuate at 27 to receive the ball in line with the center of the pendulum arm 18.

The rear ends of the plates 24 extend through the bob 22 where they have integral hooks 28 arranged to engage the outer surface of the bob when the extending ends of the plates are in their inwardly moved positions. The plates 24 are normally held in their inward or contracted positions by a rubber band 29 around projections 30 on the outer extending ends of the plates.

There is a forwardly directed pawl 31 in a longitudinal slot 32 in the bottom outside surface of the bob 22, and which pawl is pivotally mounted at its rear end by a pin 33. The forward end of the pawl 31 is tapered downwardly and outwardly and there is a hook 34 on the inner edge of said forward end for engaging the inner surface of the bob 22. Thus, by gravity, the pawl 31 normally assumes a down position.

There is a single depending tooth 35 on the bottom of the pawl 31 for engagement with teeth 36 on a rack 37 on the side of the rack mount 13. It is to be noted that the teeth 36 on the rack 37 lie within an arc generated about the center of the pendulum shaft 15.

The gun mechanism 12 includes a housing 38 which may be of cast aluminum. There is a horizontal cavity 39 in the housing, the forward end of which is open and directed toward the bob 22. Within and extending the length of the cavity 39 there is a support rod 40, one end of which is snugly received in a cylindrical recess 41, and a countersunk recessed head bolt 42 in the end of the housing 38 rigidly secures the support rod 40 in place. The forward end of the support rod 40, which extends outwardly of the housing 38, is of reduced diameter to provide a guide rod 43 on which the ball projectile 25 is slidably mounted. There is a drilled hole 44 through the ball projectile 25 for this purpose. The projectile 25 bears against the forward end of the ram 46 when the gun mechanism 12 is in its cocked position.

Slidably mounted on the forwardend of the support rod 40 there is a tubular ram 46 having a flange 47 therearound. There is a coiled compression spring 48 around the inner portion of the ram 46 and around the length of the support rod 40. The forward end of the spring 48 bears against the flange 47 and the rear end of the spring bears against a flange 49 around the support rod 40, which flange rests against the end of the cavity 39.

On the forward end of the housing 38 there is a face plate 50 which is held in place by screws 51. The back of the face plate 50 is channeled, at 52, to slidably receive a vertically movable trigger plate 53. An operating bar 54 of round stock is secured, as by welding, to the upper edge of the trigger plate 53 for pressing the latter downwardly against spring action to be described. A vertical recess 55 is provided in the lower rear surface of the face plate 50 and the lower front surface of the housing 38 for receiving a coiled spring 56. That portion of the recess 55 in the housing 38 is closed at its lower end for supporting the spring as shown in FIGURE 5. A depending finger 57 on the bottom of the trigger plate 53 extends into the spring 56 to assure alignment of the latter.

There is an opening 58 in the trigger plate 53 through which the forward end of the ram 46 projects, and the bottom of the opening is straight for engaging spaced notches 59 in the forward lower portion of the ram 46. The ram 46 is prevented from rotating about its axis by means of a vertical pin 60 which is threadedly engaged in the support rod 40. The pin 60 extends upwardly through a longitudinal slot 61 in the upper forward portion of the ram 46 and into a vertical drilled opening 62 in the face plate 50. The opening 62 provides access to a slot 63 in the top of the pin 60 for screwing and unscrewing the same, and provides additional stability to the forward end of the rod 40.

The experiments performed with a ballistic pendulum are well known to the art and are not, therefore, repeated here. However, the operations of the gun mechanism 12, the bob 22 and the pawl 31 with the rack 37 are new and novel. The support rod 40 accurately and consistently directs the projectile 25 on the guide rod 43 toward the open end of the bob 22. To cock the firing mechanism 12 the ram 46 is pressed inwardly until the straight edge of the opening 58 in the trigger plate 53 engages the first notch 59 in the ram. If greater spring force is desired for increased velocity of the projectile 25, then the trigger plate 53 ts pressed downwardly and the ram 46 is pushed farther into the housing 38 until the desired notch 59 is engaged. The mechanism is fired by lightly pressing the operator bar 54.

The plate construction 24 assures accurate location of the ball projectile 25 within the center of the bob 22 at all times by reason of the radial arrangement of the plates 24 and the arcs 27 in their inner edges. It is pointed out that the rubber band may be conveniently replaced.

The pawl 31 is not spring loaded; thus, there is a minimum of friction when the tooth 35 contacts the teeth 36 of the rack 37.

The invention is not limited to the exemplary construction herein shown and described, but may be made in various Ways within the scope of the appended claims.

What is claimed is:

1. A fixedly mounted gun comprising, a housing, a ball having a hole therethrough, said gun having a horizonal ball support rod, said rod being rigidly supported at one end in said housing, said rod having an end guide portion with a reduced diameter for slidably receiving said ball, a spring biased tubular ram slidably mounted on and encompassing said support rod over a major portion thereof for impacting said ball, trigger plate receiving notches positioned on the tubular ram adjacent the ball impacting end of said tubular ram, said trigger plate being manually operated and positioned at the forward end of the gun housing and spring biased in an upward direction to engage a selected notch on the tubular ram when said tubular ram has been moved rearwardly against the bias of the spring to a cocked position.

References Cited UNITED STATES PATENTS 335,104 2/1886 Badger et al. 124-26 3,009,452 11/1961 Barber et al. l2427 RICHARD C. PINKHAM Primary Examiner W. R. BROWNE, Assistant Examiner U.S. Cl. X.R. 124-3 7, 41 

